X-ray grain inspection apparatus



March 1956 R. KATZ ET AL X-RAY GRAIN INSPECTION APPARATUS Filed May 25,1955 IN V EN TORS. Max M/V/fl b K BY An -05 70 P ge ATTOFNEK UnitedStates Patent 2,737,594 X-RAY GRAIN INSPECTION APPARATUS Robert Katz,Max Milner, and Milford R. Lee, Manhattan, Kans.

Application May 25, 1953, Serial No. 356,956

2 Claims. (Cl. 250-53) This invention relates to an improved apparatusfor use in the X-ray inspection of samples of grain or seeds todetermine internal insect infestation and other internal physicalanomalies. It particularly relates to a novel film cassette and sampleholder which helps to produce a clear radiograph of the sample which isheld in an orderly alignment, thereby permitting rapid visual inspectionand analysis.

Your petitioners have developed techniques by which the presence anddegree of insect infestation of grain or seed is determined by X-rayradiography of grain or seed samples. In applying these techniques theequipment consists of an X-ray machine, an X-ray film in a light-tightcontainer or film cassette and a tray or sample holder which holds thegrain sample. Because of the difference in X-ray absorption between aninfested portion and an uninfested portion of a kernel of grain, it ispossible t o glifiitrentiate between infested and uninfested grain onthe finished radiograph.

An important problem is that of surveying the finished radiograph forthe number of defective kernels. When radiographing a sample of grainprepared by scattering the kernels over the surface of the film withrandom orientation and with no special grouping, the resulting film isdifficult to analyze, since the eye cannot systematically organize thepicture into an orderly sample.

An object of this invention is to provide a sample holder upon which theindividual kernels of the sample are easily and quickly oriented as asingle layer, one

kernel in thickness, and so arranged as to permit rapid inspection anddetection of defective kernels.

To minimize penumbral effects it has been found desirable to have thespecimen or sample as close as possible to the film. Therefore, anotherobject is to provide a sample holder which is an integral part of thefilm cassette, thereby placing the sample in close proximity to the filmand producing a clear picture.

It is apparent that if the grain sample and holder are placed betweenthe source of X-ray and the X-ray film, the holder must be of a materialwhich is relatively transparent to soft X-rays. Ideally, the sampleholder should have greater X-ray transparency than the sample to beX-rayed, thereby producing a dark background for the developed film.

The face of the cassette which also comprises the sample holder oralignment tray therefore must be lighttight, geometrically thin and havegreat X-ray transparency.

In the drawings:

Figure 1 is a diagrammatic illustration in section of the essentialelements of an X-ray grain testing apparatus according to the inventionshowing the relation between the various elements of the apparatus.

Figure 2 is a perspective view of a combination cassette-sample holderaccording to the invention.

Figure 3 is a perspective view of a cassette-sample holder in which thesample holder is of a modified type.

Referring to the drawings, X-ray film 11 is contained in light-tightcassette 12 which has flaps 13, rear face 14, front face 15 and latch16. Flaps 13 and rear face 14 may typically be constructed of stiffopaque paper.

Front face 15, which also acts as a sample holder, is made of a thin,colored or black sheet of paper or plastic or other material of lowatomic number and contains a series of parallel, grain-holding grooves17. Grooves 17 have a depth approximately that of one kernel of grain18.

As shown in the drawings, sample holder 15 is formed of solidconstruction. An alternative construction can be made by fabrication byfolding or stamping from a thin sheet.

To prepare a sample of grain for testing, the X-ray technician places asmall quantity of grain on the grooved surface of sample holder face 15,then scrapes a straight edge or similar device across the face, causinga single layer of kernels 18 to settle into the grooves 17 and removingthe surplus. Because grooves 17 are approximately the depth of a singlekernel, the sample retained in the grooves will be one kernel thick.

The combination film cassette-sample holder containing the X-ray filmand holding a sample of grain is then exposed to the X-ray beam.

It will be seen that the method permits rapid preparation and testing ofsamples, which is important when time is a factor, as for example, atharvest time when vast quantities of grain are in transit from farm tomarket.

Upon inspection of the exposed X-ray photograph, the grain will appearin orderly parallel lines and the number of infested kernels can becounted with ease and accuracy, since the eye of the inspector canfollow the pattern of the grooves, and the danger of erroneous orduplicative counting is minimized.

A modified form 19 of the sample holder, according to the invention isshown in Figure 3. Here the grooves 17 have been eliminated and arereplaced by a series of uniform, rectangular recesses, or pockets 20which are in symmetrical arrangement. Each of the recesses 20 has auniform depth approximating that of one kernel of grain. The preparationof samples in this case is identical with the procedure used with theholder 15 shown in Figure 2.

It will be apparent that identical recesses of still other shapes mightbe used and are encompassed in the scope of the invention.

From experimentation it has been learned that the recognition andcounting of defective kernels is most efficient if the recesses 20 areof a size to hold from about 6 to about 10 kernels, the eye of thetrained inspector being able to scan this quantity most readily.

The modified type of sample holder 19 has an advantage over the holder15 of Figure 2 in that it can accommodate grains of somewhat varyingsizes, whereas in holder 15 the size of grooves 17 must be varied foruse with grains of varying sizes.

It is apparent that many modifications may be made in the sample holderwithout departing from the spirit of the invention.

It is further apparent that the apparatus is adapted for X-rayinspection of any other small granular objects, as well as seeds orgrain.

Having thus described the invention, we claim:

1. In an X-ray granule inspection apparatus, in combination, a filmcassette and a sample holder, said sample holder forming one face ofsaid cassette, and being provided with a plurality of granule holdingrecesses, each 3 of said recesses having a depth approximately that ofone granule of said sample.

2. In an X-ray grain inspection apparatus, in combination, a filmcassette and a sample holder, said sample holder forming one face ofsaid cassette, being formed of a thin, homogeneous material having highX-ray transparency, and being provided with a plurality of grain holdingrecesses, each of said recesses having a depth approximately that of akernel of said grain.

References Cited in the file of this patent UNITED STATES PATENTSSolomon June 14, 1910 Buttolph Oct. 27, 1925 Bills "Q Sept. 13, 1932McLachlan, Jr Apr. 25, 1944 Marsh et a1. May 1, 1951

